The $1.1 million jet-black rumbling bus that has been carrying Obama through the Midwest this week was designed in part by Prevost, a motor coach manufacturer based in Quebec. The New York Post was first to report this, and Provost officials confirmed this fact to ABC News.

"We just build an empty shell of a bus, and then sell them to a converter for outfitting," Prevost's Steve Zeigler told ABC News.

The U.S. Secret Service said it purchased the vehicle from Hemphill Brothers Coach Co., which is based in Nashville, Tenn.

Hemphill, which declined to discuss the presidential bus or its business generally, assembles custom motor coaches and customizes the interiors before selling the finished product directly to individuals, businesses or the government.

"We just make the shell. We don't know anything about the end user," said Christine Garant of Prevost.

Several industry sources speculated that Hemphill may have installed an American-made engine, such as a Detroit Diesel, in the presidential bus, though that could not be immediately confirmed.

Secret Service spokesman Ed Donovan said the agency based its purchase on bus design, looking for the coach with the most available space to accommodate state-of-the-art custom security modifications.

The service acquired two of the new campaign-style buses last year as additions to the government's protective fleet.
Could the government have purchased a bus that was made entirely, or almost entirely, in America? In theory, yes.

The only U.S.-headquartered coach manufacturer, Motor Coach Industries, based in Schaumburg, Ill., also builds the country's only "buy American compliant" coach, the majority of whose parts are made here, an MCI spokeswoman said.

It's unclear whether the Secret Service considered this option.

The presidential limousine, nicknamed "the beast," was made by Cadillac, a General Motors Corp. brand, in 2009.